What is the name of the enzyme that unzips the double helix during replication

Genetic disorders can result when sister chromatids fail to seperate properly. during what phase is this problem most likely to occur?

Can a trait be both polygenic and have multiple alleles? explain why or why not.

Fill in the blank with the correct sphere label. a: ⇒ geosphere b: ⇒ biosphere c: ⇒ hydrosphere